How much did you tube pay for its contents? Zero? And they want to charge for it?

No, but they do pay to host the content and maintain the site. It's the overhead that they are probably trying to cover. Personally, I wouldn't pay for it ads or no ads, but I understand their reasoning.

I know that hosting a service such as youtube is rather expensive since I myself have a bit of web design and server knowledge, however that doesn't justify a subscription service. YouTube is currently hosted with ads and have been for years, if ads wasn't a profitable solution for Youtube then Google would've changed it's market tactics for youtube many years ago and/or shut down the service... But they haven't, therefore proving that youtube is a profitable service with how ads are served on the service right now.

And yes, you could say that Google is loosing a massive amount of profit on people who use add-blocking software... But yet again I'd like to say no to that since Google hired people a couple of people a few years ago with the intent of making a new advertisement software that counted a view even if there was software installed that blocked the advertisement script from appearing on the screen or even running... They haven't said that they succeeded in making this software, however I think they did and that they want to hide the fact that they successfully made the software like that since their biggest profit is coming from ads and they'd most likely lose a crap tom of advertisement partners if they went out and said something like that.